Astronomers have found strong evidence that a massive black hole is being ejected from its host galaxy at a speed of several million miles per hour. New observations from NASA's Chandra X-ray Observatory suggest that the black hole collided and merged with another black hole and received a powerful recoil kick from gravitational wave radiation.

"It's hard to believe that a supermassive black hole weighing millions of times the mass of the sun could be moved at all, let alone kicked out of a galaxy at enormous speed," said Francesca Civano of the Harvard-Smithsonian Center for Astrophysics (CfA), who led the new study. "But these new data support the idea that gravitational waves -- ripples in the fabric of space first predicted by Albert Einstein but never detected directly -- can exert an extremely powerful force."

Although the ejection of a supermassive black hole from a galaxy by recoil because more gravitational waves are being emitted in one direction than another is likely to be rare, it nevertheless could mean that there are many giant black holes roaming undetected out in the vast spaces between galaxies.

"These black holes would be invisible to us," said co-author Laura Blecha, also of CfA, "because they have consumed all of the gas surrounding them after being thrown out of their home galaxy."

Civano and her group have been studying a system known as CID-42, located in the middle of a galaxy about 4 billion light years away. They had previously spotted two distinct, compact sources of optical light in CID-42, using NASA's Hubble Space Telescope.

More optical data from the ground-based Magellan and Very Large Telescopes in Chile supplied a spectrum (that is, the distribution of optical light with energy) that suggested the two sources in CID-42 are moving apart at a speed of at least 3 million miles per hour.

Previous Chandra observations detected a bright X-ray source likely caused by super-heated material around one or more supermassive black holes. However, they could not distinguish whether the X-rays came from one or both of the optical sources because Chandra was not pointed directly at CID-42, giving an X-ray source that was less sharp than usual.

"The previous data told us that there was something special going on, but we couldn't tell if there were two black holes or just one," said another co-author Martin Elvis, also of CfA. "We needed new X-ray data to separate the sources."

When Chandra's sharp High Resolution Camera was pointed directly at CID-42, the resulting data showed that X-rays were coming only from one of the sources. The team thinks that when two galaxies collided, the supermassive black holes in the center of each galaxy also collided. The two black holes then merged to form a single black hole that recoiled from gravitational waves produced by the collision, which gave the newly merged black hole a sufficiently large kick for it to eventually escape from the galaxy. The other optical source is thought to be the bright star cluster that was left behind. This picture is consistent with recent computer simulations of merging black holes, which show that merged black holes can receive powerful kicks from the emission of gravitational waves.

There are two other possible explanations for what is happening in CID-42. One would involve an encounter between three supermassive black holes, resulting in the lightest one being ejected. Another idea is that CID-42 contains two supermassive black holes spiraling toward one another, rather than one moving quickly away.

Both of these alternate explanations would require at least one of the supermassive black holes to be very obscured, since only one bright X-ray source is observed. Thus the Chandra data support the idea of a black hole recoiling because of gravitational waves.

The source is located in the Cosmic Evolution Survey (COSMOS) field, a large, multi-wavelength survey.

These results will appear in the June 10 issue of The Astrophysical Journal.

Chandra and other telescopes have shown that the galaxy CID-42 likely contains a massive black hole being ejected at several million miles per hour. The main panel is a wide-field optical image of CID-42 and the area around it. The outlined box represents the more localized view of CID-42 that is shown in the three separate boxes on the right-hand side of the graphic. An image from Chandra (top box) shows that the X-ray emission is concentrated in a single source, corresponding to one of the two sources seen in deep observations by Hubble (middle box). The precise Chandra data helps astronomers narrow their ideas about what is happening in this galaxy, supporting the ejected black hole theory. Credit: X-ray: NASA/CXC/SAO/F.Civano et al; Optical: NASA/STScI; Optical (wide field): CFHT, NASA/STScI

“...according to the quantum mechanical uncertainty principle, rotating black holes should create and emit particles. Hawking radiation reduces the mass and the energy of the black hole and is therefore also known as black hole evaporation.

“Because of this, black holes that lose more mass than they gain through other means are expected to shrink and ultimately vanish. Micro black holes (MBHs) are predicted to be larger net emitters of radiation than larger black holes and should shrink and dissipate faster.”

A black hole, in and of itself, only absorbs radiation. It can be "seen" if it passes in front of a light source like a galaxy or bright nebula.

"We can see a black hole being kicked out of its home galaxy by another black hole (and its really, really bright)."

This article isn't discussing actually "seeing" the black hole, but instead the radiation emitted from gas excited as it is compressed and heated by gravity near the black hole event horizon. One point made in the article is that black holes in intergalactic space (extremely little gas) would be unobservable except for the point I made first- passing in front of a light source.

"Energy and matter cannot be created nor destroyed."

Correct.

Energy and matter simply disappear into a black hole."

Incorrect. The mass of the black hole will increase whenever either energy or mass is absorbed, as determined by E=mc2. There is an interesting issue as to whether or not certain quantum "information" (spin, for instance) is lost when matter enters a black hole. Charge is conserved, as black holes may be charged.

'However, one a black hole is kicked out of a galaxy, it will likely evaporate.'

The rate of Hawking radiation emission (same as ideal black body radiation) is thought to be inversely proportionate to mass according to:

Therefore a million solar mass black hole would be observed at a temperature of about 0.00000000000006 deg K, and would be gaining net mass from both cosmic background radiation at 2.7 K, plus any starshine or other infalling mass source.

In the extremely distant future, if the expanding universe theory is correct, the cosmic background radiation might go low enough to cause a net mass loss...but we're talking trillions of years plus. Even then the rate of evaporation would be very slow.

Bear in mind that the radius of that million solar mass black hole's event horizon is about three million kilometers, so there's not really that much surface area to radiate from - that's only about four times larger than the Sun.

"Question... Does the numerator on the right hand side have anything to do with Avogadro's number?"

The same thought crossed my mind, but Avogadro's number is dimensionless, so I think it's just a coincidence.

"Personally, I really hope heat death is not the ultimate fate of the universe. It would kind of make this whole enterprise a rather large waste of time."

I suppose it is what it is. On any human timescale it's rather meaningless really.

On the other hand, if the multiverse exists as posited in recent physics, I suspect it encompasses every possibility. Not only of every possible universe based on our set of physical laws, such as a universe for every grain of sand on the beach being a different color (or shape, or size, or composition) but every other possibility you can imagine, including oscillating universes and steady-state universes. Then, there would be the universes that don't follow our exact set of physical laws, for every permutation you can imagine (F=ma/3, F=ma/pi, d=(1/2)vt, gravity being proportional to the cube of distance etc.).

Just imagine, in a high-order infinite number of those universes, Barack 0bama wasn't elected President in 2008! :-)

I believe that concept of universes would entail the highest possible order of mathematical infinity, Aleph Infinity. I find the concept satisfying in that it would fulfill every possible concept of physical symmetry, something our particular universe doesn't do, for instance in the department of matter/antimatter quantitative asymmetry.

It sort of brings a new perspective of omniscience and omnipotence, eh? :-)

It can be "seen" if it passes in front of a light source like a galaxy or bright nebula.

AND YET... if you look at the photos accompanying this article, the BRIGHT SPOTS in them are claimed to be 'black holes', are they not?

This article isn't discussing actually "seeing" the black hole, but instead the radiation emitted from gas excited as it is compressed and heated by gravity near the black hole event horizon.

So... exactly where is the 'event horizon', and if the center is 'black' and only the 'ring' or horizon gives off radiation, then surely we would see a 'ring' shaped effect instead of a globular emanation. The whole concept of a 'hole' implies a two-dimensional object.

If a black hole has an event horizon, can one see it from the 'side', or from 'behind' it? Would it not have to have an event horizon no matter which direction you approached it from? If true, then the 'horizon' that we 'see' from Earth only exists to those on Earth. To someone from another far away galaxy, the 'horizon' would exist only to them.

One point made in the article is that black holes in intergalactic space (extremely little gas) would be unobservable except for the point I made first- passing in front of a light source.

So... they would be strong enough to suck up the light, but not strong enough to suck up the source of the light?

The mass of the black hole will increase whenever either energy or mass is absorbed, as determined by E=mc2.

I would agree. However, how do we measure the mass of a black hole, since the energy and matter 'disappear' into it?

(Please understand I am not 'arguing' or telling you that you are wrong, or I am right. I am only trying to learn, and the way to learn is to question those with some knowledge. Many times by asking these 'silly' questions, I learn quite a bit. Whether I 'accept' your answers or not, I do extremely appreciate your input)

I do 'believe' that the entity we describe as a 'black hole' is something that is beyond our ability to understand or describe, at this time.

God saw that the light was good, and he separated the light from the darkness.

Which was either a reference to the fact that the Earth 'spins', or that even with an infinite amount of stars, giving off unimaginable amounts of light, it is still dark at night, due to a very delicate balance between the amount of light giving stars, and the immensity of space.

True, but we were discussing "seeing" the black hole, and generally speaking we don't see things by reflecting planets and stars from them...

'It can be "seen" if it passes in front of a light source like a galaxy or bright nebula.'

"AND YET... if you look at the photos accompanying this article, the BRIGHT SPOTS in them are claimed to be 'black holes', are they not?"

The bright spots are indirect evidence of the black hole(s), as pointed out by my next remark:

This article isn't discussing actually "seeing" the black hole, but instead the radiation emitted from gas excited as it is compressed and heated by gravity near the black hole event horizon.

Note the "bright spots" are shining brightly in the X-ray spectrum, indicating a very energetic region. The only things that ever shine brightly in that spectral region on the Earth's surface are nuclear explosions.

"So... exactly where is the 'event horizon', and if the center is 'black' and only the 'ring' or horizon gives off radiation, then surely we would see a 'ring' shaped effect instead of a globular emanation."

There's a lot of good material out there about black holes, it'd be good for you to read some if you're interested. I'll try and hit a couple of high points here.

The event horizon is a 3D shape surrounding the singularity. If there's no rotation (unlikely) it would be spherical, otherwise it's an oblate spheroid similar to the Earth or Sun.

In a nutshell, a black hole forms when there's so much mass in a neutron star that the intrinsic "strength" of neutrons to "push each other apart" is overcome by gravity. Essentially matter itself collapses under the pressure. Then, nothing can stop the neutron star from collapsing towards a point mass, called a singularity. Current physics cannot describe the conditions at the singularity. Charge and spin are both conserved for a black hole (a black hole may have spin, which distorts the shape of the event horizon as I mentioned before).

Perhaps fortunately for physics ;-) the singularity itself can't be observed, due to the event horizon. The event horizon occurs at the distance from the singularity at which the escape velocity becomes "c" (the speed of light). As I mentioned before, it is a 3D shape surrounding the singularity. Due to some associated details of relativity, an outside observer will never witness the final collapse of matter of the original object, as intense gravitational fields slow down time from the viewpoint of such an observer. Black holes were originally called "frozen stars" for this reason.

According to current physics, nothing can escape from within the event horizon, since it would have to exceed the speed of light to do so. In the case of a rocket, which can climb away from a body without exceeding the escape velocity given enough energy, an infinite amount of energy would be required, so that that won't work either.

One thing that might have contributed to your confusion on this point is the concept of the "accretion disk". Accretion disks commonly form when material with angular momentum falls inward. Our solar system almost certainly formed from an accretion disk, for instance. They have been directly observed in many different astronomical observations.

The black holes discussed in the articles almost certainly possess accretion disks, and they are likely the source for almost all of the observed energy. However, gas surrounding the central region is also heated and excited, and will produce radiation as well. It's also not clear at what angle we're observing the accretion disk, from directly "above" or "below" it would appear circular, same as a spherical cross-section. There are also often jet phenomena associated with accretion disks that might point towards us and both directly radiate or excite gas into radiating.

"The whole concept of a 'hole' implies a two-dimensional object."

That's one of your big misconceptions... A black hole's gravity field is in fact a 3D entity, although some visualizations sure make it look 2D, for instance the one where space-time is represented as a membrane with a funnel-shaped distortion. That is to give you an idea of how gravity distorts space-time, but it does it in 3D, not 2D. A spacecraft's path will curve around a massive object regardless of the 2D plane its orbit inhabits.

"If a black hole has an event horizon, can one see it from the 'side', or from 'behind' it? Would it not have to have an event horizon no matter which direction you approached it from? If true, then the 'horizon' that we 'see' from Earth only exists to those on Earth. To someone from another far away galaxy, the 'horizon' would exist only to them."

Again, you're conflating a 2D concept with a 3D reality.

"One point made in the article is that black holes in intergalactic space (extremely little gas) would be unobservable except for the point I made first- passing in front of a light source.

"So... they would be strong enough to suck up the light, but not strong enough to suck up the source of the light?"

The gravity from a million solar mass black hole is down to a 1G (Earth surface gravity) field at only ~55 AU from the black hole. 1 AU is the distance from the Earth to the Sun, 150,000,000 km. So, again using the inverse square law of gravitational force, at a distance of 55,000 AU the gravity field from a million solar mass black hole is down to one millionth of a G. 55,000 AU may seem like a long way, but in fact a single light year is ~63,000 AU. So, you can see that the gravity from such an object is quite weak at a range of many light years (tens to billions).

The black hole not only absorbs light directly, but its gravitational field makes light bend, an effect called "gravitational lensing". Such an effect has been directly observed in astronomy, as light bends around galactic clusters. It has also been observed as starlight is bent around the Sun during a solar eclipse.

"The mass of the black hole will increase whenever either energy or mass is absorbed, as determined by E=mc2.

"I would agree. However, how do we measure the mass of a black hole, since the energy and matter 'disappear' into it?"

In astronomy, the mass of things is often determined by the gravitational effects on other things. For instance, the mass of the large black hole at the center of our own galaxy was verified using the speeds of stars orbiting near it. Nothing except a large black hole would enable the stars to attain the observed speeds, as measured by Doppler shifts of spectral lines. Here's a good explanation from here.

Data taken by astronomer Andrea Ghez (video here) was able to show the complete orbits of stars orbiting the galactic center at whiplash inducing speeds. With orbits that would fit inside our solar system, some of these stars had orbital periods of less than 10 years! The only way to get an orbit that small and that fast is to have a supermassive black hole in the center of the Milky Way. Calculations estimate its mass at 4 million times the Suns mass! No object other than a black hole is dense enough to fit in such a tiny space. Her work, and parallel investigations using the European Southern Observatorys Very Large Telescope (likewise for infrared imaging), show conclusively that a massive black hole sits in the heart of our galaxy. This black hole and the environment it creates can explain all other unusual observations, from x-ray flashes to radio emission. Such supermassive black holes are proving to be common at the centers of bright galaxies, and their growth produces the spectacular phenomena of active galactic nuclei.

"(Please understand I am not 'arguing' or telling you that you are wrong, or I am right. I am only trying to learn, and the way to learn is to question those with some knowledge. Many times by asking these 'silly' questions, I learn quite a bit. Whether I 'accept' your answers or not, I do extremely appreciate your input)"

I'd suggest that "the way to learn is to question those with some knowledge" is instead a way to learn. Books are useful, and there's a ton of free information on the web.

"I do 'believe' that the entity we describe as a 'black hole' is something that is beyond our ability to understand or describe, at this time."

Actually black holes have been described in excruciating (mathematical) detail, and based on observational data either black holes exist, or something that we currently don't have a clue about exists that acts exactly as we'd expect a black hole to act. I strongly suspect black holes exist pretty much as described in the literature.

I spent a bit more time on this than I'd intended, but it was fun reviewing some of what I'd read years ago regarding black holes. I also ran across this paper today, which shows some of the interesting work going on with astronomical observations.

Thank you, again, for spending so much time providing some very informative responses. : )

Books are useful.

Yes, they are. And while reading a book on the subject(s) would help ME, it wouldn't help anyone else. (I play a dummy on the internet, but I do it for a reason)

I'll ping everyone, since this may be of some general interest.

... AND THAT is exactly the reason. I asked questions a layman might ask, and you provided detailed and informative responses (to the best of your knowledge) and now perhaps at least dozens, if not hundreds of people will get a chance to READ IT here on FR.

You also did a very good job of presenting the information in layman's terms. A person who is skilled in one particular area (like physics or astronomy), but who cannot present the information in terms that most people can understand, is not quite as 'bright' as he thinks he is.

Consider me as Tom Sawyer. I got you to paint the fence, and now the whole neighborhood is 'brighter' because of it.

P.S. There was a thread here on FR recently where 'scientists' (a term used very loosely) declared that there is no 'black hole' at the center of the Milky Way Galaxy. What do you think of that claim?

As you said before, that measurement is based on the effect the 'black hole' has on the 'mass' around it. Considering that we are now finding that our 'estimates' of the actual 'mass' ...out there... are not quite correct, then are our estimates of the mass of a black hole incorrect as well?

Earlier this morning, on a thread about FREE ENERGY from WATER (keyword: BLACKLIGHT), it was suggested that 'dark matter' or 'dark energy' was made from Hydrinos. (so 'new' a word that even spell checker doesn't like it).

The best way to sum this all up is that all our 'knowledge' is subject to revision, as we 'learn' more about the Universe.

BTW, the Military turned over operation of some unneeded Spy Satellites which will give us an 'imaging' ability improvement of 100X the power of the Hubble Space Telescope.

Yes, as PreciousLiberty mentioned Hawkings radiation will slowly (very slowly) evaporate a black whole. He did throw in that this evaporation is currently over whelmed by the cosmic background radiation, which I was unaware of (and I am thinking about). Also current theory is knowledge is not lost in a black whole either, Hawkins was proven wrong there.

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